The Paris climate agreement requires us to cut CO2 emissions by 95%, right across the board; so that means energy, industry, and also mobility. In a city like Rotterdam, mobility is responsible for around 20% of all emissions. So it is not the biggest polluter, but it is certainly an important and complex one. The method used in Rotterdam is called CO2 roadmapping”; It is taken the sum total of vehicles in the city and break it down into various categories. What modes of transport are used in Rotterdam? How many are there? What are they used for? Knowing the contribution made by each mode of transport, Rotterdam can calculate the yields per individual measure.